SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff3896b534ded66047cdc40ae5efbb6b4fc6f665393fd49a97b969d31da1b6a4' 
  AND token = 'Q2yO4HApgKdWO7f+KoP2WrrbCuZAzMinOd9/B7g3yuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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