SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7040f97ce7c4218bbb1206514205af2a828ab4a40cf4145c40ff540220a6382b' 
  AND token = 'mjxaDZgyY6xycxquUPd5CxI+hhfMtkBUWJjxinANmak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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