SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '884dcdb5e20afee49c234886504363f237e058e4d0baddf0aec74ebdaf04c343' 
  AND token = 'TWjTfq/qAGAQ2W4REL9OO7TtpSZCecWdx8ux9jWiFko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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