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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b57dbbeaedb764d9f144eb1d050a93a52bb71bbb1ee23441c8dffcb274c569b' 
  AND token = 'UPKX/c66ExhxNDlixQCJ9xIdrFXLBtkKqoLo5ysZ/TE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}