SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc0ec70b5e2ce70f20b0a41984cd348c29aebcf197a6f9be274140eeab238d66' 
  AND token = 'Kd7aS0WowoFjHSXIusfC5LjiA8GM6IvLPCbR3jrz0oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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