SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a268a4b089d207e29e37ed0436346771c99a50755a9404acfdc6200fc3c2c469' 
  AND token = 'FaA5yuWJ52BqqSRseoSUjtIKWYpBHviyjOSk3mYNwEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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