SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a66c37f37a5a9df97bf266f2c21c8b1de083127c8fa4a8a13375b934f25fe975' 
  AND token = '1NeKBjEYukPcAt7R/EC3rSjbX8VgMtR0qp5HZ2GQYUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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