SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '644797c96a1a41a12b8967107b7af526dcc3156fe738607c6697bfbf95535ad5' 
  AND token = 'MRlOLahFWSubfNoGvDz7NppqmYq3XVGLG4my66WNqhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}