SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c14e634677759ca45a79af42fceb16f1ec3581a587dff5cf6b4ae730a57a939' 
  AND token = 'vQYZxB6xHMmcq0gEg0pfZc2gwK/VNRMkZshuNZ6jNJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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