SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '394202e8824cb00f7faab3b9e07555cd0623856b1fd77c18bf0ee07f40eb76ee' 
  AND token = 'pH+wn1s7USSWcSTVqlnohqFD2ZLvBT4hvPRLgdFgubo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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