SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '886f420a0dbdca690add7c0b18ec372b33a1d7430dfbe937b74f8fcd54b87f54' 
  AND token = 'QG2dRkPHmqVmwe9cznNocN/vnht75oiYPNAgEHJSXjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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