SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '733e02ab066a8d74222bc5992a22b69da6579153acf98db2d26f989c9ddd2bed' 
  AND token = 'AFa+2UUqSfPybCdGcr7RwMfUC3eusRsM7/Yv9O9cl/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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