SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27724c89a582c7778f6f38643ad2e4e59497a51f107a0f9271a48e36d155d619' 
  AND token = 'Yvy7SuoLtgUgwpCC4GlttOnB7wKcwElFmPJO0UVjiyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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