SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab64575cd28cdd9b7240c29542c82fb4b29bf8c002b540d31181bf810f369547' 
  AND token = 'UI/8HIgFdHTJz3cX98JFZm4X+hW7r/nxxaUV2QKNieI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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