SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2255b8cc3203f918685dd84438f66b13d17f9a41ef81320f0c5cd556a50cd15' 
  AND token = 'sktOlrU6qHE/0BrOOohdfNJHsR4ZA7bOzRAXG1mJ62Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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