SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '114c6b2d9dea9d722ee2cc10b73ebd288f6a27702dc91aa7a8e0a5cca276f803' 
  AND token = 'h1JFMVitqGTst0CbpCpplNGwMg1VWOLOF6yundbsIug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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