SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c110ebbc199ab982dbbf0235b467cec65cb31b485c5c4bfec8ed1c23158ba274' 
  AND token = 'tpLtHhpoUgtHLjCuTq9FObKqf/RaM/lbgvG2rIaDs7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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