SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f52041196ac0ca3dae0e2b23005c7af6a534eae45619fb3e4361c14d553e565' 
  AND token = 'AJdCp1GSdVQLCFdoAKru1vpBV005+IpidyXRwHMC2Oo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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