SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf4fc1ea1b3879e1326826f8902f7588f7662e5bfa46f0beff7093fb30410dde' 
  AND token = 'tptCK6sL6Yih7wHNled83Y919k2Xunck3PdTZrNej5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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