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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ca0b3ed4001f8968c13f32b7d9dedd72da3eb067cd20e7ef41725f75dadc28' 
  AND token = 'NRGomMhHc3xXTSIghPpS9PTSWwDbDd5CWPM304M5lS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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