SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bc2a0468341c49080d83efa72fab174924709ba0afc369d2b287fdc6381d25b' 
  AND token = 'KiRWgv5dT/PuHAZZwpQcoyJS7VoKTfBlAJCIJXULeBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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