SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c9227ed1550d1ebc6a4822a3722e7e003596f397b0de6ece3b7e31274b19939' 
  AND token = 'GuI/EcrWadUCdgawuG+hVldqvR6jTasJLV8tRnZ0z4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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