SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '564b9142c5973602cd85b1682577fb7092f7a8ba3b7268d5bca078f4bfeb9c5d' 
  AND token = 'IEj6ov//1egftG4lx8FGG1BMQ03UXvNMg3+1aC+ibsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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