SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3084d1ffd547bf24da6c1d21333e94ac760e27d00d6528df6c87aec3e4d91a8d' 
  AND token = '8E3RoM57ZgIBZtJ1iAvqtOaHpCbuJKUIlFO/vD/yAJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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