SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b477a9478aeabfaee899ba45f471318f880bff5da4b97ae5746eb7ee7abfb645' 
  AND token = 'hYHX4PilCcw5WYaQ+P+YPpY/6HGmZL25CRyfR4GhP1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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