SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4fd72cf69ff98023a19744be57e5f770bc0c099fb66a59b9308486939479b46' 
  AND token = 'jvZtG1jy/R4dq1xkYkr+4vnceWwDlCu4253KBYdzjyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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