SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f75c7bb539da7795774d4d4cea64bd69dc06e166f817c507885157bf8a650422' 
  AND token = 'WCxrj/kUyhawcpAgzTsLgD3w1lTbNrl8QmcQn1N6ukQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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