SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd292a9dc3ae5f808e98db98885ae79f522c6a535f59948fbc2af470f90323913' 
  AND token = 'LqbPdNbLNcvV4a3oKZAuEtvKibUk83G/KnGT04pj48w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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