SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e7d50d90332f2e15ce705decbec6039497eba8e4de2dcd6689ee20271fd3b0c' 
  AND token = 'ec+XVQxn7ABnSQ6kH7Ipo+XkRV9wMCKzTO5Gpkjqhp4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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