SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c99c56900dda9f0b50267029d78a5e9629322414283e5b39574d3c7c16b13889' 
  AND token = 'OldPbDCr2tVr95exqGpX1ZW8MJFIITOij29QKxEoMLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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