SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b0226b5aaf40a90b7ad1d2c8dd59fc3516ebe7e81fc567c7f48b8d2f738e474' 
  AND token = 'oE6qoNAbQOhFmPpnysLdXoDaNnQqIp2BtMuamOvxzy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}