SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f0489b93a2126b891346f18127995141696a3227b989cd6f8c0a1339da5f307' 
  AND token = 'XUVvhg8rfSX5s3+ZteAOJFK4tiSbsBXC+lhnQcf+tJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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