SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9c6813bf09c8143d1b471a9d9fe5c3296959c6bd72f46236569afc2133e144a3' 
  AND token = 'QE95MMHs0YGobg6TW01uTdh0WhPivr2KRWYOX6SGGEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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