SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4053cf86be1595bd528e6d65a62bea20be5deefeb8bc7dc59534715c5ab02103' 
  AND token = '2YwczPHeRItBgunBZFXTg3Zox7qxsbGFlrCmHxOtqLw=' 
  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"
    }
  }
}