SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e4749254f9c66301ae5b714c1a75354ad148aae79a14459a8f5e57ae260475b' 
  AND token = 'iQ19CWbD+ldBaeGkzY6Rzl1ECtJ+ZDAlPUl7FpIhvU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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