SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5768d46c558b446599dac010fa92c34bff7248c0da7cf354cfb77966b2d8a88b' 
  AND token = 'TXltfw5W2x0GQYakqY5bn26hEth/sxCkRnEIJV1VG5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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