SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0261e4636e15502836af458bcb322d0bec137ad229c3c4c7624047dfff7a581f' 
  AND token = 'TrhFQW/6VoKle0/ae1IYrCC3nS6+2gYFTN3yLNfeTCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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