SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '321f52f825d2ff736c6b9df3438da66bf5b906dbfd12830321ae82a67955c8d0' 
  AND token = 'ZOoi7x3emlGoKqhjL+obNCzRLZt5jPPWlebmvr8Z+WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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