SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc9cdf2ca1ca1edcec1a5e87607edaa1a73b2414d5e8954c98ecd29e45ce1c2' 
  AND token = 'jn6+ooRuKmRV8Unuj24V12Mvo+rqQda/F6CFz6NqoLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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