SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc59da9372f63282e3b83553ee437456a29d03fc13f815fd78cbe40342661996' 
  AND token = '0RZrUaxglheqQ36ZqJfz/+iWfM24zxc8YstCJutt3ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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