SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46bfc438818fa98b0d9975d9bd4498e5af523c2d48559199a1cf05bece37e304' 
  AND token = 'FAVeCMGBICrsMdTlHMXkVRWkpKEEJ0t4ItIxyWTfto0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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