SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a626feb48849e2973382561e2ea0c9d4b5113566257e98dba8b228da18545240' 
  AND token = 'ZvnBkRtrxlgA7wrbnJpSwOmbKura8YQQwkN8g3QUKF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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