SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e021d42d50a3b9332dd91f3e1d93d685d8007fea4779d6db2edaa8d157d85ef2' 
  AND token = 'd5pmDEaby4DP+RS1yOomKYA6UxKFMlcCq5XU2R8Tr6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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