SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '314b1603af8fce774477937c082d40b14984bb8fcd2b4f3d98a432489f01f91e' 
  AND token = 'tSwrRA4/PYZ8ZcWSCWeVSEWUaZLOlyq2cYIGv5BOpKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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