SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b7772dd1717285e93b4dc2c352fe922d6e17f0c09d0fbc6666994482b6b75c0d' 
  AND token = 'zeihMooB9BePJFIpB38PWW3FQq+cfd+h4f0nrWCPwL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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