SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c874f88e347cde72202eb9ab86d771b7cff924b760086a2097bd663b5b742692' 
  AND token = 'e9m6ym1fXU86YhP/fYpxCfYGvjPpMe53/Z61YWs9Y8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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