SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff6df52bee15c784e4ed715540c3f7976b6b74443be2c16caa7def9830e2256a' 
  AND token = 'Cicrp+rx1S/jTM5g5wl57gSz6qPphtaLta8qPKv3G/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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