SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd152abfcb76f796354670c244272a742d1deed55e5d7b462de6da126ff70077b' 
  AND token = 'XPwLdagHBtP5VVyfb5K8nSNltUO6Edtf0UqWwpgfG2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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