SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ef7fc68c9d5209a4a6a74843eec390143375817b56448d7de01d59321a82006' 
  AND token = 'WtuFWSvfBQUwdh17sMSdxnhTJEctDHGLV8lfcFxXdn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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