SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '978622ef172456079648e4a63d9d196860088a2a4d09f24708ca23e9c8e529bf' 
  AND token = 'UBUtR7I337AHQ5xw7ygIS7NFuDklfGzfrfGpBoSb6HY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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