SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d6ce48a26d52ea0af8dca409204c10e7b0fc4538cbdcb3c56debf6789c8a38' 
  AND token = 'eCrXxrmxYjuFdGhkIC0+iYRlH56SpCb/TJxCJ4GwZ7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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