SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6acee2bfb608ee94bd662a7816172c6fa3149069e7f6109ffd02f4acea15ed76' 
  AND token = 'DmcwLpyeUHN/opWjC+6QFUPA+IQ7y2BP3dNft+FcASw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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