SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efad19fea2fd6bd3b6ccb5cae95acc61318d22b98e79a51b7a0896741f3d1315' 
  AND token = 'xGUevHPqs6CZF8s0DxQAwjgA55O+ifL+EpTpWF1Dbao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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