SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c059f6579619df34a3c15c860b66ac89a4877dfdd50ac6a8f2b35617e742bb35' 
  AND token = 'epy+7C70Jpw17QrfDSauFRMDjq1GmdzYEBnC+tb/KsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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