SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b81d71c6c9c2439453b94b4a2b0745a71185fc4a0271e635406412494a2f1dd5' 
  AND token = 'IYTEmjIkLsq48QI1MpREKWhOECIAszA9wmzm+cCxOaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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