SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba1cac18967d8955ead5aaf56daaecdc8a578ae1f6c2273add93fcb5a94147d8' 
  AND token = 'x6ro+Zwe3tZaYJuDDxa89IvgJ4Ds2MP1IGbUzytPKBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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