SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e94e6f47812ad475da5d75c1c5166398e12de39d2729d4d5a042078d890448b' 
  AND token = 'wa5IKkjbwMVi9YDZrhMj8g3TWPQRmGXZmHnT3IQF5+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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