SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7938f86ca9b341b9a611f7a86dfb1dd76a93b31d37c912cef2cf4515905f3508' 
  AND token = 'XVz5K6jN7p1hX9J1Ha/x7vn2VSGl9f/CqZuHPKMscXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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