SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f879a5b65f72654d5dfe1ac2976df265b950241e26b988d163c0df0e7f5d5d9' 
  AND token = '1Iu/Zx8WSD+oQJl/GN7VFQLjT7MnnLRmkVjFbjlAJUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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