SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '86ea646bdc93572d7bcd5e63202973f417546e039fbea6cc4279364e7e0f4650' 
  AND token = '2vsUPAVlFsjNza6/QBUsKLwTrYmWRj7AvYHGmcZEhu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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