SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56b7d7df658b6b594134d055be5f9010043695f12751b1cb467b2449cf0cea2' 
  AND token = 'PKP+ruKM8K2jqJiuZ8zDnBNuFIF20jE6U6m2Qe50YLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}