SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18754fa137632e110e0ec504ca6ade8c30c1cec34699e7fe1e8d400dfe063bd6' 
  AND token = 'uPG15A0xNaw3SAsI6WTpTM70UNK0awKY4gb0VYESp20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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