SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f8fa24656217679bc1c4fb8a1e2d683fae2461c44a3567f016cce02fc1c5434' 
  AND token = 'VdjWeJhF96wxmPTbG2LPReQ1egJQcEYNpg8JdknurBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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