SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14bc543bb1e87722b1586be08983eddce7fc68be1072dbac238a132321c283f1' 
  AND token = 'Ja8Xddd4lqRZJDaCcWmqifTAWDm0XC/2e0yoI0A70hY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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