SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7da3a9c7ca3125407f732befffd6886a4b904fbfed25689159f14d221941dece' 
  AND token = 'EY+goiIlmosT9vseEhc3GPOE7CnSsdxO68gKh9h6UbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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