SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a79f417e6fd1b3de56b86d7e8a9ff866f0e8e5991fce94a8a2c51a617231ac7e' 
  AND token = 'Kg1mVtiDehs9m+24v6ZbWBmqDPDwFFwRtlzINpLIXQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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