SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cf607c574bcf381aa1481c937ad2899fb8be443e52bfb0691adc9ff5521a212' 
  AND token = '4Cmq8MpSdmGYbi2LNJpuWD6iWQUpsXq2xIh7Kt8l+KM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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