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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4dbcf188eee2122212cde9a4c30d3cc2b91ae6de6bfefb00cfd4ce73dc968a0' 
  AND token = 'Kc7dp2Cz0s1k2vwd4XmvbFDU6dLg4ifAhT3gFyXKFQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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