SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c4ce97c0fd5512dbaddcfe6b8920d96fe4c1beb455ae51feb4655c9266b6651' 
  AND token = 'CUMQpSdZzIep8bUKHUoxFBIdJew5m3TD1ceEDHm/rxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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