SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a77d8909d769a06dfa13614092c9fcafc346754bc1f351402cb132d559248ba' 
  AND token = 'xQdPmgMClwNsgnytIOk3VIEGV1pfG+Sd8z4oObxDiBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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