SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fee9e66879415cc2eec6cfe31de5b63d8401c79ce27d1a8d4a380132d2645a84' 
  AND token = 'Gsu+3xMr/WT9BOvjswdh/zjogYhmU/JDqqc0f/cUqyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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