SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d1dcf79a09f8df17289c271a9eb0bd07763f1af5b868e3dfd90f3d8b5b9432' 
  AND token = 'ZPYfScW+CxhH+JYEJ86IR5vOsZVL7nzd5TJ/IAGgW60=' 
  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"
    }
  }
}